The present invention relates to a method of polishing the surface of a work into a mirror surface.
Recently, materials for electronic parts are mostly required to have mirror-finished surface free of disorder of crystalline structure or residual stress. In the semiconductor material such as single crystal of silicon or the like, a chemical polishing is effected as the final processing, making positive use of the high purity of the single crystal. However, most of materials for industrial use are polycrystal materials and are not entirely free from the presence of impurities. If such materials are subjected to a chemical polishing, steps are formed at the grain boundaries due to anisotropy of the crystals or the elution or residue of the impurities takes place so that it is not possible to form a mirror-finished surface.
In the conventional mirror-finishing method for metallic products such as rolls, which surfaces are removed while attaining an amorphous state of the surface, the hardness of the material is increased, or the fatigue rupture strength is increased. This method, therefore, can advantageously be used for certain purposes. In case of the materials of electronic parts, however, it is essential to form a mirror-finished surface without altering the nature of the material itself so that the conventional mirror-finishing process cannot apply satisfactorily.